Carrier board and power module using same

ABSTRACT

A carrier board and a power module using the same are disclosed. The carrier board includes a main body, two metal-wiring layers and at least one metal block. The main body includes at least two terminals and a surface. The two terminals are disposed on the surface. The two metal-wiring layers are disposed on the main body to form two parts of metal traces connected to the two terminals, respectively. The at least one metal block is embedded in the main body and connected to one of the two terminals. A thickness of the two parts of metal traces is less than that of the metal block. The two terminals connected by the two parts of metal traces have a loop inductance less than or equal to 1.4 nH calculated at a frequency greater than 1 MHz.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priorities to China Patent Application No.202010075506.4, filed on Jan. 22, 2020, and China Patent Application No.202110064816.0, filed on Jan. 18, 2021. The entire contents of theabove-mentioned patent applications are incorporated herein by referencefor all purposes.

FIELD OF THE INVENTION

The present disclosure relates to the field of power electronics, andmore particularly to a carrier board and a power module using the same.

BACKGROUND OF THE INVENTION

As an important part of power conversion, modern power electronicequipment is widely used in the power, electronics, motor and energyindustries. Ensuring long-term stable operation of power electronicequipment and improving power conversion efficiency of power electronicequipment have been an important goal of those skilled in the art.

As the core component of modern power electronic equipment, powersemiconductor devices directly determine the reliability and powerconversion efficiency of power electronic equipment. In order to designa reliable, safe, and high-performance power electronic equipment, it isdesirable that the power semiconductor device has low voltage stress andlow power loss. Power semiconductor devices used in power electronicequipment operate in a switching mode, and high frequency switching willinduce a high current change rate di/dt in the wires. Therefore, avoltage Vs is caused by the changed current applied on the strayinductance Ls and is calculated as followed.Vs=Ls×di/dt

Therefore, a higher voltage spike is caused by larger stray inductancewhen the current change rate keeps in constant. The voltage spike willreduce the reliability of the device and increase turn-off-loss of thedevice. The device is allowed to switch faster with smaller gateresistance as the stray inductance is reduced, which have lowerswitching loss and higher efficiency of the converter. Moreover, thevoltage spikes not only affect the efficiency, but also cause theelectromagnetic interference problems.

At the same time, due to the unavoidable presence of parasiticinductance in the power loop, the high switching frequency of the powerdevice causes a rapid voltage change, which will cause the EMI in thecircuit to exceed the standard.

In addition, the performance and the thermal management of a powersemiconductor device are closely related to each other. Good thermalmanagement is essential to improve the conversion efficiency, powerdensity and reliability of power devices. The reasons are as thefollowing. (1) At a lower operating temperature, the on-state losses ofa power device such as MOSFET and IGBT will be reduced, and it isbeneficial to the improvement of system efficiency. (2) In many cases,the power density is directly determined according to the magnitude ofheat energy, because the power converter is a system used to processpower conversion. Generally, a semiconductor device is the device with alot of losses, and the tolerable temperature of the semiconductor deviceis limited within a certain range. If the semiconductor device isoperated over the limitation, the working ability of the semiconductordevice might be lost, or the performance of the semiconductor devicemight be deteriorated sharply. Therefore, the heat dissipation system isrequired to control the temperature of the semiconductor chip within anacceptable range. (3) Generally, the cost of heat dissipation accountsfor a large proportion of the system cost. (4) The life of thesemiconductor device is closely related to the operating temperature. Inthe electronics field, there is usually such engineering experience thatthe life is reduced by half when the operating temperature is raised by10 degrees. A lower operating temperature can effectively extend thelifespan of the device.

On the other hand, the output capacitance of the power device, such asthe capacitance between the drain and the source of the MOSFET device,has a great influence on the switching loss of the power device. Inorder not to increase the switching loss, when the wiring relationshipof each component is configured, it is also necessary to reduce theoutput capacitance of the power device.

Therefore, there is a need of providing a carrier board and a powermodule using the same to obviate the drawbacks encountered by the priorarts and achieve the purpose of reducing the parasitic inductance andthe EMI and improving the heat dissipation at the same time.

SUMMARY OF THE INVENTION

An object of the present disclosure is to provide a carrier board and apower module using the same. By optimizing the arrangement of eachcomponent, the purpose of reducing the parasitic inductance and the EMIis achieved. It facilitates the power module structure to be assembledeasily and firmly. At the same time, it is beneficial to reduce thevolume of the power module and improve the entire power density of thepower module.

Another object of the present disclosure is to provide a carrier boardand a power module using the same. By utilizing a carrier boardincluding two metal-wiring layers and at least one metal block toconnect two switches in series to form a bridge arm, the area of thehigh-frequency loop is reduced, and the corresponding loop parasiticinductance is reduced. In addition, when the bridge arm formed by thetwo switches and a clamping component of the power module areelectrically connected in parallel on the carrier board through the twometal-wiring layers, it is helpful for reducing the clamping inductancein the power module. With the at least one metal block embedded in thecarrier board, it is more helpful for improving the heat dissipationperformance of the power module. By partially overlapping theprojections of the at least two metal-wiring layers, the at least onemetal block and the two switches connected to each other in series onthe surface of the carrier board, two high frequency loops decoupledfrom each other are formed, and the parasitic inductance in the twohigh-frequency loops is reduced. The current of one first high-frequencyloop flows through the metal-wiring layer on the surface of the carrierboard, and the current of another high-frequency loop crosses throughthe metal-wiring layer on the surface of the carrier board. Notably, thecurrent that flows through the metal-wiring layer in the horizontaldirection can be ignored. At least, the two high-frequency loops arepartially decoupled, and the mutual influence is eliminated. Moreover,it is easy to realize the connection of the carrier board with thebridge arm including the two series-connection switches. It isbeneficial for reducing the cost and enhancing the reliability. Sincethe bridge arm including two series-connection switches is disposed onthe carrier board including at least one metal block embedded therein,it facilities the power module to combine with two heat dissipationdevices to achieve the double-sided heat dissipation and reduce thethermal resistance. Furthermore, the purposes of reducing the costs,enhancing the reliability of the power module and improving theheat-dissipation capacity are achieved. The metal-wiring layer on thesurface of the carrier board can be realized with a thinner thickness,and combined with the metal block prefabricated and embedded in thecarrier board to reduce the manufacturing costs and further enhance thereliability of the carrier board. When the two switches and the clampingcomponent of the power module are directly disposed on the carrierboard, it is beneficial for simplifying the assembly structure, reducingthe cost, simplifying the manufacturing process, and improving the yieldand reliability of the product.

A further object of the present disclosure is to provide a power module.By arranging the metal conductive component on the side of the switchesand the clamping component away from the carrier board, the metalconductive component is kept away from the trace of carrier board, whichconnects the switches and the clamping component to the positiveterminal and the negative terminal therethrough, so that the outputcapacitance formed by the switches of the power module is reduced, andthe parasitic inductances in the two high frequency loops areeliminated. An optimized power module is achieved. Moreover, the metalconductive component and the bridge arm including two switches connectedin series can be prefabricated into an integrated structure, and theconnection with the carrier board is easy to realize. It is beneficialfor reducing the cost and enhancing the reliability. Two switches areconnected to each other in series to form a bridge arm and disposed onthe carrier board, and the bridge arm is formed by connecting twoswitches in series through the metal conductive component. Moreover, thebridge arm is connected with the clamping component in parallel throughthe carrier board, so as to form two high frequency loops decoupled fromeach other. Since the two high frequency loops are partially decoupled,the mutual influence is eliminated. Moreover, the metal-wiring layer onthe surface of the carrier board can be realized with a thinnerthickness, and combined with an integrated structure prefabricated bythe metal conductive component and the two switches, so as to reduce themanufacturing costs. When the two switches and the metal conductivecomponent of the power module are directly disposed on the carrierboard, it is beneficial for simplifying the assembly structure, reducingthe cost, simplifying the manufacturing process, and improving the yieldand reliability of the product.

In accordance with an aspect of the present disclosure, there isprovided a carrier board. The carrier board includes a main body, atleast two metal-wiring layers and at least one metal block. The mainbody includes at least two terminals and at least one surface. The atleast two terminals are disposed on the at least one surface. The atleast two metal-wiring layers are disposed on the main body to form atleast two parts of metal traces, which are connected to the at least twoterminals, respectively. The at least one metal block is embedded in themain body, spatially corresponds to and is connected to one of the atleast two terminals. A thickness of the at least two parts of metaltraces is less than a thickness of the at least one metal block. The atleast two terminals connected by the at least two parts of metal traceshave a loop inductance, which is less than or equal to 1.4 nH when theloop inductance is calculated at a frequency greater than 1 MHz. Thecarrier board is helpful for reducing the clamping inductance in thepower module and improving the heat dissipation performance.

In accordance with an aspect of the present disclosure, there isprovided a power module. The power module includes a carrier board andtwo switches. The carrier board includes a main body, at least twometal-wiring layers and at least one metal block. The main body includesat least two terminals, an upper surface and a lower surface. The atleast two terminals are disposed on the upper surface. The at least twometal-wiring layer are disposed on the main body to form at least twoparts of metal traces, which are connected to the at least twoterminals, respectively. The at least one metal block is embedded in themain body, spatially corresponds to and is connected to one of the atleast two terminals. A thickness of the at least two parts of metaltraces is less than a thickness of the at least one metal block. Twoswitches are disposed on the upper surface and connected to each otherin series through the at least two terminals to form a bridge arm. Aprojection of the at least one metal block on the lower surface is atleast partially overlapped with a projection of the two switches on thelower surface.

In accordance with an aspect of the present disclosure, there isprovided a power module. The power module includes a carrier board, afirst switch, a second switch, at least one metal block, a clampingcomponent and a metal conductive component. The carrier board includesan upper surface, a lower surface, a positive terminal and a negativeterminal. The first switch and the second switch are disposed on theupper surface and connected to each other in series to form a bridge armelectrically connected between the positive terminal and the negativeterminal. The at least one metal block is disposed between the uppersurface and the lower surface, and electrically connected to the firstswitch and/or the second switch. The clamping component is disposed onthe upper surface and electrically connected in parallel with the bridgearm through the carrier board. The metal conductive component isconnected from a common node of the first switch and the second switchto an output terminal. The metal conductive component is located at aside of the first switch and the second switch facing away from theupper surface.

The above contents of the present disclosure will become more readilyapparent to those ordinarily skilled in the art after reviewing thefollowing detailed description and accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic cross-sectional view illustrating a carrier boardaccording to an embodiment of the present disclosure;

FIG. 1B is a schematic cross-sectional view illustrating a power moduleaccording to a first embodiment of the present disclosure;

FIG. 2A is a circuit diagram showing a half-bridge power module of thepresent disclosure;

FIG. 2B is an equivalent circuit diagram showing the power module of thepresent disclosure;

FIG. 3 is a circuit diagram showing a half-bridge power module having aclamping circuit of the present disclosure;

FIG. 4 is a top view illustrating a power module according to a secondembodiment of the present disclosure;

FIG. 5 is a schematic cross-sectional view illustrating the power moduleof FIG. 4 and taken along the line A-A;

FIG. 6 is a schematic cross-sectional view illustrating the power moduleof FIG. 4 and taken along the line C-C;

FIG. 7 is a schematic cross-sectional view illustrating the power moduleof FIG. 4 and taken along the line B-B;

FIG. 8 is a partial cross-sectional view illustrating the power moduleof FIG. 6 and taken along the line D-D;

FIG. 9 is another partial cross-sectional view illustrating the powermodule of FIG. 6 and taken along the line D-D;

FIG. 10A is a schematic cross-sectional view illustrating a firstexample of the switch of the present disclosure;

FIG. 10B is a schematic cross-sectional view illustrating a secondexample of the switch of the present disclosure;

FIG. 11 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to a third embodiment of thepresent disclosure;

FIG. 12 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to a fourth embodiment of thepresent disclosure;

FIG. 13 is a schematic cross-sectional view illustrating a power moduleaccording to a fifth embodiment of the present disclosure;

FIG. 14 is a schematic cross-sectional view illustrating a power moduleaccording to a sixth embodiment of the present disclosure;

FIG. 15 is a schematic cross-sectional view illustrating a power moduleaccording to a seventh embodiment of the present disclosure;

FIG. 16 is a schematic cross-sectional view illustrating a power moduleaccording to an eighth embodiment of the present disclosure;

FIG. 17 is a schematic cross-sectional view illustrating a power moduleaccording to a ninth embodiment of the present disclosure;

FIG. 18 is a schematic cross-sectional view illustrating a power moduleaccording to a tenth embodiment of the present disclosure;

FIG. 19 is a schematic cross-sectional view illustrating a power moduleaccording to an eleventh embodiment of the present disclosure;

FIG. 20 is a schematic cross-sectional view illustrating a power moduleaccording to a twelfth embodiment of the present disclosure;

FIG. 21 is a schematic cross-sectional view illustrating a power moduleaccording to a thirteenth embodiment of the present disclosure;

FIG. 22 is a schematic cross-sectional view illustrating a power moduleaccording to a fourteenth embodiment of the present disclosure;

FIG. 23 is a schematic cross-sectional view illustrating a power moduleaccording to a fifteenth embodiment of the present disclosure;

FIG. 24 is a schematic cross-sectional view illustrating a power moduleaccording to a sixteenth embodiment of the present disclosure;

FIG. 25 is a schematic cross-sectional view illustrating a power moduleaccording to a seventeenth embodiment of the present disclosure;

FIG. 26 is a schematic cross-sectional view illustrating a power moduleaccording to an eighteenth embodiment of the present disclosure;

FIG. 27 is a schematic cross-sectional view illustrating a power moduleaccording to a nineteenth embodiment of the present disclosure;

FIG. 28 is a schematic cross-sectional view illustrating a power moduleaccording to a twentieth embodiment of the present disclosure;

FIG. 29 is a schematic cross-sectional view illustrating a third exampleof the switch of the present disclosure;

FIG. 30 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-first embodiment of the present disclosure;

FIG. 31 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-second embodiment of the present disclosure;

FIG. 32 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-third embodiment of the present disclosure;

FIG. 33 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-fourth embodiment of the present disclosure;

FIGS. 34A to 34E are schematic cross-sectional views showing amanufacturing process of a power module according to an embodiment ofthe present disclosure;

FIG. 35 is a schematic cross-sectional view illustrating the carrierboard produced in the manufacturing process of the power module;

FIG. 36 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-fifth embodiment of the present disclosure;

FIG. 37 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-sixth embodiment of the present disclosure;

FIG. 38 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-seventh embodiment of the present disclosure;

FIG. 39A shows a first example of a driving clamping circuit of thepresent disclosure;

FIG. 39B shows a second example of a driving clamping circuit of thepresent disclosure;

FIG. 39C shows a third example of a driving clamping circuit of thepresent disclosure;

FIG. 40 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-eighth embodiment of the present disclosure;

FIG. 41 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-ninth embodiment of the present disclosure;

FIG. 42 is a schematic cross-sectional view illustrating a power moduleaccording to a thirtieth embodiment of the present disclosure;

FIG. 43 is a schematic cross-sectional view illustrating a power moduleaccording to a thirty-first embodiment of the present disclosure; and

FIG. 44 is a schematic cross-sectional view illustrating a power moduleaccording to a thirty-second embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present disclosure will now be described more specifically withreference to the following embodiments. It is to be noted that thefollowing descriptions of preferred embodiments of this disclosure arepresented herein for purpose of illustration and description only. It isnot intended to be exhaustive or to be limited to the precise formdisclosed. For example, the formation of a first feature over or on asecond feature in the description that follows may include embodimentsin which the first and second features are formed in direct contact, andmay also include embodiments in which additional features may be formedbetween the first and second features, such that the first and secondfeatures may not be in direct contact. In addition, the presentdisclosure may repeat reference numerals and/or letters in the variousexamples. This repetition is for the purpose of simplicity and clarityand does not in itself dictate a relationship between the variousembodiments and/or configurations discussed. Further, spatially relativeterms, such as “beneath,” “below,” “lower,” “above,” “upper” and thelike, may be used herein for ease of description to describe one elementor feature's relationship to another element(s) or feature(s) asillustrated in the figures. The spatially relative terms are intended toencompass different orientations of the device in use or operation inaddition to the orientation depicted in the figures. The apparatus maybe otherwise oriented (rotated 90 degrees or at other orientations) andthe spatially relative descriptors used herein may likewise beinterpreted accordingly. When an element is referred to as being“connected,” or “coupled,” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. Although the wide numerical ranges and parameters of thepresent disclosure are approximations, numerical values are set forth inthe specific examples as precisely as possible. In addition, althoughthe “first,” “second,” “third,” and the like terms in the claims be usedto describe the various elements can be appreciated, these elementsshould not be limited by these terms, and these elements are describedin the respective embodiments are used to express the differentreference numerals, these terms are only used to distinguish one elementfrom another element. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of example embodiments.Besides, “and/or” and the like may be used herein for including any orall combinations of one or more of the associated listed items.Alternatively, the word “about” means within an acceptable standarderror of ordinary skill in the art-recognized average. In addition tothe operation/working examples, or unless otherwise specifically statedotherwise, in all cases, all of the numerical ranges, amounts, valuesand percentages, such as the number for the herein disclosed materials,time duration, temperature, operating conditions, the ratio of theamount, and the like, should be understood as the word “about”decorator. Accordingly, unless otherwise indicated, the numericalparameters of the present invention and scope of the appended patentproposed is to follow changes in the desired approximations. At least,the number of significant digits for each numerical parameter should atleast be reported and explained by conventional rounding technique isapplied. Herein, it can be expressed as a range between from oneendpoint to the other or both endpoints. Unless otherwise specified, allranges disclosed herein are inclusive.

In order to achieve low parasitic inductance and good heat dissipationof a power devices or systems, the present disclosure provides a carrierboard and a power module using the same. FIG. 1A is a schematiccross-sectional view illustrating a carrier board according to anembodiment of the present disclosure. FIG. 1B is a schematiccross-sectional view illustrating a power module according to a firstembodiment of the present disclosure. In the embodiment, the carrierboard 410 of the power module 1 includes a main body 101, at least twometal-wiring layers (for example a first metal-wiring layer 431 and asecond metal-wiring layer 432) and at least one metal block (for examplea first metal block 421, a second metal block 422 and a third metalblock 423). The main body 101 includes at least two terminals, an uppersurface 102 and a lower surface 103. Preferably but not exclusively, theat least two terminals are selected from the at least two of a positiveterminal TP, a negative terminal TN and an output terminal TO, which areall disposed on the upper surface 102. The first metal-wiring layer 431and the second metal-wiring layer 432 are disposed within the main body101 to form at least two parts of metal traces, which are connected tothe at least two of the positive terminal TP, the negative terminal TNand the output terminal TO, respectively. In the embodiment, any one ofthe first metal block 421, the second metal block 422 and the thirdmetal block 423 is embedded in the main body 101, spatially correspondsto and is connected to one of the positive terminal TP, the negativeterminal TN and the output terminal TO. In other embodiments, two of thepositive terminal TP, the negative terminal TN and the output terminalTO are omitted, and only one metal block is embedded in the main body101. In addition, the power module 1 using the same carrier board 410includes a first switch 451 and a second switch 452 disposed on theupper surface 102 of the carrier board 410. In the embodiment, the firstswitch 451 and the second switch 452 are connected in series through thepositive terminal TP, the negative terminal TN and the output terminalTO to form a bridge arm.

FIG. 2A is a circuit diagram showing a half-bridge power module of thepresent disclosure. FIG. 2B is an equivalent circuit diagram showing thepower module of the present disclosure. Please refer to FIGS. 1A to 2B.In the embodiment, as shown in FIG. 2A, the bridge arm is formed byconnecting the first switch 451 and the second switch 452 in seriesthrough the positive terminal TP, the negative terminal TN and theoutput terminal TO. In the related art, as shown in the circuit diagramof the half-bridge power module shown in FIG. 2A, the half-bridge armincludes a first switch 451 and a second switch 452. The first switch451 and the second switch 452 are connected in series between thepositive terminal TP and the negative terminal TN. Moreover, the outputterminal TO is electrically connected to a common node of the firstswitch 451 and the second switch 452. In other words, the P electrode isconnected to the first switch 451, such as a pad of the switch S1. The Nelectrode is connected to the second switch 452, such as a pad of theswitch S2. The first switch 451 and the second switch 452 are connectedto each other and are connected to the O electrode.

Moreover, in the embodiment, the power module 1 is for example but notlimited to an embedded power module. Preferably but not exclusively, thepower module 1 further includes a clamping component 440, such as acapacitor. As shown in FIG. 2B, it illustrates an equivalent circuitdiagram of a power module with a clamping capacitor. When a clampingcapacitor is disposed within the power module 1, and the first switch451 and the second switch 452 are turned off, the surrounding area ofthe corresponding high-frequency loop will be reduced and the loopparasitic inductance will also be reduced. If there is no clampingcapacitor disposed within the power module 1, the value of the loopparasitic inductance is Lout+Lin. As the clamping capacitor Cin isdisposed within the power module 1, the value of the loop parasiticinductance becomes Lin. Therefore, by disposing the clamping capacitorCin into the loop, the parasitic inductance can be reduced.

FIG. 3 is a circuit diagram of a power module with another clampingcircuit. In the embodiment, two Zener diodes Z1 and Z2 are connected inparallel with the first switch S1 and the second switch S2,respectively, and then connected in series. The clamping circuit formedby the series connection of two Zener diodes can play the role ofvoltage division.

FIG. 4 is a top view illustrating a power module according to a secondembodiment of the present disclosure. FIG. 5 is a schematiccross-sectional view illustrating the power module of FIG. 4 and takenalong the line A-A. FIG. 6 is a schematic cross-sectional viewillustrating the power module of FIG. 4 and taken along the line C-C.FIG. 7 is a schematic cross-sectional view illustrating the power moduleof FIG. 4 and taken along the line B-B. FIG. 8 is a partialcross-sectional view illustrating the power module of FIG. 6 and takenalong the line D-D. FIG. 9 is another partial cross-sectional viewillustrating the power module of FIG. 6 and taken along the line D-D. Inthe embodiment, the structures, elements and functions of the powermodule 1 a are similar to those of the power module 1 of FIG. 2, and arenot redundantly described herein. In the embodiment, the power module 1a includes a carrier board 410, a first switch 451, a second switch 452and a clamping component 440. The carrier board 410 is shown in a bolddashed frame as shown in FIG. 5. The first switch 451 and the secondswitch 452 correspond to the first switch S1 and the second switch S2 inFIG. 2B, respectively. Preferably but not exclusive, the first switch451 and the second switch 452 are MOSFET, IGBT, BJT or other types ofswitches. The present disclosure is not limited thereto. The carrierboard 410 includes a first metal block 421, a second metal block 422, athird metal block 423, a first metal-wiring layer 431 and a secondmetal-wiring layer 432. The second metal block 422 is located betweenthe first metal block 421 and the third metal block 423. The main body101 of the carrier board 410 includes an upper surface 102 and a lowersurface 13. The clamping component 440 is disposed on the upper surface102 of the carrier board 410. The first metal-wiring layer 431 and thesecond metal-wiring layer 432 are located at a side of the first metalblock 421, the second metal block 422 and the third metal block 423,which is the same side of the at least one metal block facing the uppersurface 102. In the embodiment, the first metal-wiring layer 431 and thesecond metal-wiring layer 432 are located between the clamping component440 and the second metal block 422. The first switch 451 and the secondswitch 452 are disposed on the upper surface 102 of the carrier board410. The first switch 451 and the second switch 452 are connected to theclamping component 440 through the first metal-wiring layer 431 and thesecond metal-wiring layer 432. The first switch 451 includes a first padT1 and a second pad T2. The second switch 452 includes a first pad T1′and a second pad T2′. Taking MOSFET as an example, the first pad s T1,T1′ represent the drain, the second pad pad s T2, T2′ represent thesource, and the third pad s (not shown) represent the gate. In otherembodiments, the first switch 451 and the second switch 452 are forexample but not limited to two-terminal devices, such as diodes. Thepresent disclosure is not limited thereto. In the embodiment, the firstpad T1 of the first switch 451 is connected to the first metal block421. The second pad T2 of the first switch 451 is connected to thesecond metal block 422 through the second metal-wiring layer 432. Thefirst pad T1′ of the second switch 452 is connected to the second metalblock 422 through the second metal-wiring layer 432. The second pad T2′of the second switch 452 is connected to the third metal block 423. Inthe embodiment, a projection of the first switch 451 on the lowersurface 103 of the carrier board 410 is at least partially overlappedwith a projection of the first metal block 421 or the second metal block422 on the lower surface 103 of the carrier board 410. Moreover, aprojection of the second switch 452 on the lower surface 103 of thecarrier board 410 is at least partially overlapped with a projection ofthe second metal block 422 or the third metal block 423 on the lowersurface 103 of the carrier board 410.

In the embodiment, FIG. 6 and FIG. 7 indicate a clamp-circuit loop andthe main-power loop formed by the power module 1 a, respectively. Pleaserefer to FIGS. 5 and 6. The current of the clamp-circuit loop flowsthrough the first metal block 421, the first switch 451, the secondmetal block 422, the second switch 452, the third metal block 423, theclamping component 440 and the first metal-wiring layer 431. As shown inFIG. 6, the high-frequency current flowing through the firstmetal-wiring layer 431 and the high-frequency current flowing throughthe first switch 451, the second switch 452 and the second metal block422 have opposite directions and are equal in magnitude. Theclamp-circuit loop is also defined as high frequency loop. Moreover, thearea of the high frequency loop is affected by the distance between thefirst metal-wiring layer 431 and the first pads T1, T1′ or the secondpads T2, T2′ of the two switches, and the distance between the firstmetal-wiring layer 431 and the second metal block 422. Under the printedcircuit board technology used, the above distances are about 100 μm. Inthat, the area of the high-frequency loop in the cross section isreduced greatly. Therefore, with the structure shown in the embodiment,in the cross-sectional direction, the area of the high-frequency loop issmall, and the corresponding loop parasitic inductance is very small.Preferably but not exclusively, the loop inductance is less than orequal to 1.4 nH when the loop inductance is calculated at a frequencygreater than 1 MHz.

Moreover, please refer to FIGS. 5 and 7. In the embodiment, the currentof the main-power loop flows from the first metal block 421 into thefirst pad T1 of the first switch 451, further from the second pad T2 ofthe first switch 451 into the second metal block 422, then from thesecond metal block 422 into the first pad T1′ of the second switch 452,and finally from the second pad T2′ of the second switch 452 into thethird metal block 423. In the embodiment, the current of the main-powerloop crosses through the first metal-wiring layer 431, and the part ofthe current flowing through the first metal-wiring layer 431 in thehorizontal direction can be ignored. Therefore, the current of themain-power loop and the current of the clamp-circuit loop are at leastpartially decoupled in the flowing paths, and the mutual influence iseliminated. Because of the separation of the clamp-circuit loop and themain-power loop, the current of the main-power loop is not transmittedthrough the first metal-wiring layer 431. Therefore, the firstmetal-wiring layer 431 can be thinner. Preferably but not exclusively,the thickness of the first metal-wiring layer 431 is less than 70 μm.With the thinner wiring layer, it is beneficial for reducing themanufacturing cost and the thickness of the carrier board 410.Furthermore, the filling of the insulation-material layer of the packagebody is improved, and the reliability of the product is enhanced. Inaddition, with such structure, the current path of the main-power loopis very smooth, and the length of the current path is greatly reduced soas to reduce the impedance of the current path. Consequently, the lossof the current path is reduced.

In the embodiment, the cross sectional view in FIG. 6 shows theclamp-circuit loop and the cross sectional view in FIG. 7 shows themain-power loop. The structures of the two cross sectional views arestaggered in the direction perpendicular to the paper surface, and thestaggering number can be one or more. The occurrence numbers of the twocross-section structures need not be equal. That is, the firstmetal-wiring layer 431 located between the first switch 451 and theclamping component 440 is used to construct a high-frequency-circuitloop and the main-power-circuit loop, respectively. Similarly, the firstmetal-wiring layer 431 located between the second switch 452 and theclamping component 440 is also used to construct ahigh-frequency-current loop and the main-power loop, respectively. Inaddition, it should be particularly noted that the metal connectingcomponent on the side of the first switch 451 and the second switch 452away from the carrier board 410 can be smaller than or beyond the rangeof the chip in the direction perpendicular to the paper surface. Thatis, the chips of the first switch 451 and the second switch 452 and theconnecting metal on the side away from the carrier board 410 need not bepresent in a cross-sectional view at the same time. It will not beredundantly described hereafter. FIGS. 8 and 9 are two different partialcross-sectional views illustrating the power module of FIG. 6 and takenalong the line D-D. In FIG. 8, the region of the first metal-wiringlayer 431 connected to the second pad T2 of the first switch 451 and thesecond metal block 422 is designed as an integral part, and the regionof the first metal-wiring layer 431 connected to the first pad T1′ ofthe second switch 452 and the second metal block 422 is designed as anintegral part. Moreover, in FIG. 9, the region of the first metal-wiringlayer 431 connected to the second pad T2 of the first switch 451 and thesecond metal block 422, and the region of the first metal-wiring layer431 connected to the first pad T1′ of the second switch 452 and thesecond metal block 422 are realized by holes and wiring.

In the embodiment, the first switch 451 and the second switch 452 aredisposed above the first metal block 421 and the third metal block 423,respectively. The first metal block 421 and the third metal block 423are separated from each other, and it is helpful for improving thethermal interaction between the first switch 451 and the second switch452 effectively, thereby improving the heat dissipation of the firstswitch 451 and the second switch 452. The large-area metal overlappedwith the projection of the first switch 451 and the second switch 452 onthe lower surface 103 of the carrier board 410 is used not only forcurrent flowing but also for heat dissipation. It is helpful forreducing the thermal resistance of the carrier board 410 from the firstswitch 451 and the second switch 452 toward the lower surface 103.Preferably but not exclusively, the copper is used for the metal block.Since the volumetric specific heat capacity of copper is larger, theability of the first switch 451 and the second switch 452 to resistinstantaneous large current can be improved.

In addition, the carrier board 410 of the power module 1 a includes thefirst metal-wiring layer 431 and the second metal-wiring layer 432. Whenthe carrier board 410 is further equipped with a driving clamp circuitto meet stricter requirements, the driving clamp circuit can beoverlapped with the first metal-wiring layer 431 and the secondmetal-wiring layer 432, and the current directions of the loop arereversed in the first metal-wiring layer 431 and the second metal-wiringlayer 432, so as to reduce the loop inductance effectively. The drivingclamp circuit can be for example but not limited to a circuit shown inthe dashed frame in FIG. 39A, FIG. 39B, or FIG. 39C. Taking FIG. 39A asan example, the switch S1 is the first switch S1 in the aforementionedpower module, and the device S3 in the dashed frame is connected to thegate and source of the switch S1. The device S3 is a part of drivingcircuit for the switch S1. More specifically, the device S3 can be usedto clamp the voltage between the gate and source of the switch S1. Thedifference between the circuits shown in FIG. 39B and FIG. 39A is thatthe driving clamp circuit has changed. The driving clamp circuitincludes a resistor R, a bipolar transistor S4 and a diode D1. FIG. 39Cprovides another variation. The driving clamp circuit can be a capacitorC connecting the gate and source of the switch S1. The driving circuitor the driving clamp circuit of any switch on the carrier board 410 ofthe power module 1 a can be connected through at least two metal-wiringlayers located at the same side of the metal block. Part of the firstmetal-wiring layer 431 and the second metal-wiring layer 432 are usedfor the traces of the loop. The projections of the traces of the loop onthe lower surface 103 of the carrier board 410 are almost overlapped. Itis helpful for reducing the loop parasitic inductance greatly andachieving a good clamping effect.

In the embodiment, a multilayer wiring region 710 is further disposedout of the first metal block 421 and the third metal block 423 tofurther integrate more functions, such as a driving circuit and acontrol circuit. Preferably but not exclusively, the multilayer wiringregion 710 is a prefabricated multilayer printed circuit board. Aplurality of prefabricated metal conductors are arranged in the openingwindows of the printed circuit board, and then the carrier board isformed by a lamination process for the printed circuit board. Thus, thetechnical solution is not only suitable for integrated power devices,but also suitable for the system-level integration. In addition, thecarrier board 410 of the present disclosure is produced by a printedcircuit board manufacturing process, and it is suitable for massproduction, and has the advantages of fast delivery and low cost. Inaddition, the devices disposed on the carrier board 410 can be realizedby discrete devices, which are manufactured with a large scale easilyand can be tested individually, thereby further improving themanufacturability and cost of the product.

In the embodiment, the first switch 451 and the second switch 452 arefor example but not limited to packaged devices. For example, FIGS. 10Aand 10B are schematic cross-sectional views illustrating differentexamples of the switch in the present disclosure. In the embodiment, forexample, the switches for the first switch 451 and the second switch 452are packaged and led out through three electrodes. The three electrodesof the packaged switch are led out in the same plane or different planesthrough the metal connectors 501. Preferably but not exclusively, themetal connectors 501 of the switch are completely exposed on the surfaceof the packaged switch. Certainly, the side of the switch without theelectrode is covered by the insulating material. FIG. 10A shows apackage form of a discrete power device. Preferably but not exclusively,the switch S0 is a MOSFET, and includes a first pad T1 representing thedrain, a second pad T2 representing the source, and a third pad T3representing the gate. For a vertical device, the second terminal T2representing the source and the third pad T3 representing the gate areusually arranged on one side of the bare chip, and the first pad T1representing the drain is arranged on the opposite side. The lead-outsurfaces of the switches in FIG. 10A and FIG. 10B are both lowersurfaces. The first pad T1 of the switch S0 in FIG. 10A is disposed onthe metal connector 501 on the lower surface. The second pad T2 isconnected to the metal connector 501 on the upper surface throughsolder, sintered material or conductive paste, and is led to the metalconductor 501 on the lower surface through the metal conductor 501 onthe upper surface to realize electrode lead-out. The third pad T3 is ledout to the lower surface through the metal conductor 501 on the uppersurface of the switch S0 and coplanar with the metal connector 501 onthe lower surface. The electrode lead-out is achieved. In anotherembodiment, the pad is led out by bonding wires. The second pad T2′ andthe third pad T3′ of the switch S0′ in FIG. 10B are disposed on themetal connector 501 on the lower surface, and the first pad T1′ isconnected to the metal connector 501 on the upper surface throughsolder, sintered material or conductive paste, and is led to the metalconductor 501 on the lower surface through the metal conductor 501 onthe upper surface to realize electrode lead-out. The present disclosureis not limited thereto. In other embodiments, DirectFET, CanPAK, theembedded package, PowerPAK, SOT263 and other SOT series are applicablefor packaging. In order to further improve the switching characteristicsof the device, the Kelvin connection method can be adopted for thecontrol electrode. Certainly, the present disclosure is not limitedthereto. Furthermore, two or more switches connected in parallel can bepackaged in the same structure.

On the other hand, in the embodiment, the thicknesses of the first metalblock 421, the second metal block 422 and the third metal block 423 aregreater than or equal to 0.3 mm. In an embodiment, the thicknesses ofthe first metal block 421, the second metal block 422 and the thirdmetal block 423 are less than 0.3 mm. In the embodiment, a thickness ofthe at least two parts of metal traces formed by the first metal-wiringlayer 431 and the second metal-wiring layer 432 is less than a thicknessof the at least one of the first metal block 421, the second metal block422 and the third metal block 423. When the thicknesses of the firstmetal block 421, the second metal block 422 and the third metal block423 are greater than or equal to 0.3 mm, the metal block not onlyprovides good electrical and thermal conductivity, but also providesgood structural support. Compared with the traditional method of usingmulti-layer printed circuit boards to handle high frequency circuits andexternal bus bars to handle power circuits, it saves a lot ofinstallation and connection parts and avoids the possibility of multipleinsulating media in the vertical path of the device by utilizing themetal block of the present disclosure. Moreover, it further improves theheat dissipation performance of power device.

FIG. 11 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to a third embodiment of thepresent disclosure. In the embodiment, the structures, elements andfunctions of the power module 1 b are similar to those of the powermodule 1 a of FIG. 5, and are not redundantly described herein. In theembodiment, the power module 1 b further includes a first heatdissipation device 1002 and a first thermal-conductive and insulatingmaterial 1001. The first heat dissipation device 1002 and the firstthermal-conductive and insulating material 1001 are disposed on thelower surface 103 of the carrier board 410. The first metal block 421,the second metal block 422, and the third metal block 423 are connectedto the first heat dissipation device 1002 through the firstthermal-conductive and insulating material 1001. As shown in FIG. 11,the first metal block 421, the second metal block 422, and the thirdmetal block 423 are connected to the first heat dissipation device 1002through the first thermal-conductive and insulating material 1001 forheat dissipation. In the embodiment, the first heat dissipation device1002 is for example but not limited to a fin-type heat sink. In otherembodiments, the first heat dissipation device 1002 is aheat-dissipation-column-type heat sink or a water-cooling heat sink. Inthe embodiment, the heat generated from the first switch 451 and thesecond switch 452 is dissipated through the heat dissipation paths intwo directions. Taking the first switch 451 as an example, the heatdissipation paths include a first path transferred from the switchthrough the first metal block 421, and a second path transferred fromthe switch through the metal connector 501 connected to the second padT2 of the first switch 451 to the second metal block 422. Generally, thethermal resistance of the metal connector 501 connected to the secondterminal T2 of the first switch 451 is larger than that of the firstmetal block 421 or the second metal block 422 due to the smallcross-sectional size of the heat dissipation path. Therefore, thethermal resistance of the first path is smaller than that of the secondpath. Generally, the thermal resistance of the first path is about halfof the thermal resistance of the second path, or even smaller.Therefore, the first path is the main heat dissipation path. Similarly,the main heat dissipation path of the second switch 452 is a pathtransferred through the third metal block 423.

Notably, in the embodiment, the first metal block 421 and the thirdmetal block 423 are located in the main heat dissipation paths. Namely,the first metal block 421 and the third metal block 423 play the role ofproviding not only a path for current in the circuit, but also the mainheat dissipation paths in the structure of the power module 1 b. Forexample, in order to achieve a better heat dissipation effect, the widthof the metal block overlapping with the first switch 451 or the secondswitch 452 on the lower surface 103 of the carrier 410 is relativelywide. In the embodiment, the widths of the first metal block 421, thesecond metal block 422 and the third metal block 423 are different, soas to reduce the thermal resistance on the main heat dissipation paths.For example, the first metal block 421 and the third metal block 423have the same width and are wider than the second metal block 422.Certainly, the present disclosure is not limited thereto. In anembodiment, the widths of the first metal block 421, the second metalblock 422 and the third metal block 423 are the same. In otherembodiments, the widths of the first metal block 421, the second metalblock 422 and the third metal block 423 are completely different.

It should be noted that the power module 1 b further includes athermal-conductive and insulating layer, which is disposed on the lowersurface 103 of the carrier board 410 to perform the function ofthermally conductive and insulating. Certainly, the present disclosureis not limited thereto.

FIG. 12 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to a fourth embodiment of thepresent disclosure. In the embodiment, the structures, elements andfunctions of the power module 1 c are similar to those of the powermodule 1 a of FIG. 5, and are not redundantly described herein. In theembodiment, the power module 1 c further includes a second heatdissipation device 1004 and a second thermal-conductive and insulatingmaterial 1003. The second heat dissipation device 1004 and the secondthermal-conductive and insulating material 1003 are disposed over thefirst switch 451 and the second switch 452. The first switch 451 and thesecond switch 452 are connected to the second heat dissipation device1004 through the second thermal-conductive and insulating material 1003.Preferably but not exclusively, in the embodiment, the metal connector501 above the first switch 451 is also connected to the heat sinkthrough a high thermal-conductive and insulating material, so that adouble-sided heat dissipation is achieved. In the power module 1 b ofFIG. 11 and the power module 1 c of FIG. 12, each thermal-conductive andinsulating material is an organic material, such as a highthermal-conductive and insulating film, or a ceramic material. Inaddition, the thermal-conductive and insulating material is not limitedto a single-layer material. Preferably but not exclusively, thethermal-conductive and insulating material is a composite layermaterial, such as a ceramic having one side/two sides composite organiclayer, or a high-insulation organic film having one side/two sidescomposite high thermal-conductive layer.

FIG. 13 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to a fifth embodiment of thepresent disclosure. In the embodiment, the structures, elements andfunctions of the power module 1 d are similar to those of the powermodule 1 a of FIG. 5, and are not redundantly described herein. In theembodiment, the power module 1 d further includes a firstthermal-conductive and insulating material 1001. In the embodiment, thefirst thermal-conductive and insulating material 1001 is disposed underthe first metal block 421, the second metal block 422 and the thirdmetal block 423. By prefabricating the first thermal-conductive andinsulating material 1001, the power module 1 d is more convenient touse.

FIG. 14 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to a sixth embodiment of thepresent disclosure. In the embodiment, the structures, elements andfunctions of the power module 1 e are similar to those of the powermodule 1 a of FIG. 5, and are not redundantly described herein. In theembodiment, the first metal block 421, the second metal block 422 andthe third metal block 423 are formed by the thin metal layers havingthickness of less than 0.3 mm. The carrier board 410 can be manufacturedby a printed circuit board technology to reduce cost.

Moreover, in order to improve the heat dissipation capability of theswitch in the downward direction, in the embodiment, the power module 1e includes a fourth metal block 424, a fifth metal block 425 and a sixthmetal block 426 disposed on the lower surface 103 of the carrier board410. In the embodiment, the bottoms of the first metal block 421, thesecond metal block 422, and the third metal block 423 are furtherconnected to the fourth metal block 424, the fifth metal block 425 andthe sixth metal block 426, respectively, which are thinner and have athickness greater than or equal to 0.3 mm. The connection method isrealized by welding or sintering. Certainly, the present disclosure isnot limited thereto.

FIG. 15 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to a seventh embodiment of thepresent disclosure. In the embodiment, the structures, elements andfunctions of the power module 1 f are similar to those of the powermodule 1 a of FIG. 5, and are not redundantly described herein. In theembodiment, the first switch 451, the second switch 452 and the clampingcomponent 440 are disposed on two sides of the carrier board 410 of thepower module 1 f. In the embodiment, the projection of the clampingcomponent 440 on the lower surface 103 of the carrier board 410 isbetween the projections of the first switch 451 and the second switch452 on the lower surface 103 of the carrier board 410. A thirdmetal-wiring layer 433 is disposed between the clamping component 440and the second metal block 422. One terminal of the clamping component440 is connected to the first metal block 421 through the thirdmetal-wiring layer 433, and another terminal of the clamping component440 is connected to the third metal block 423 through the thirdmetal-wiring layer 433. In the embodiment, the bottoms of the firstmetal block 421, the second metal block 422, and the third metal block423 are further connected to the fourth metal block 424 and the sixthmetal block 426, respectively, which are thinner and have a thicknessgreater than or equal to 0.3 mm. The connection method is realized bywelding or sintering. In that, the heat dissipation capability of thefirst switch 451 and the second switch 452 in the downward direction isimproved.

FIG. 16 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to an eighth embodiment of thepresent disclosure. In the embodiment, the structures, elements andfunctions of the power module 1 g are similar to those of the powermodule if of FIG. 15, and are not redundantly described herein.Different from the power module if of FIG. 15, in the embodiment, thepower module 1 g further includes a seventh metal block 427 disposed onthe upper surface 102 of the carrier board 410 for the high-powercurrent passing therethrough.

FIG. 17 is a schematic cross-sectional view illustrating a power modulewith a heat dissipation device according to a ninth embodiment of thepresent disclosure. In the embodiment, the structures, elements andfunctions of the power module 1 h are similar to those of the powermodule 1 b of FIG. 11, and are not redundantly described herein. In theembodiment, the carrier board 410 further includes a fourth metal-wiringlayer 1301. The fourth metal-wiring layer 1301 is disposed under thesecond metal block 422. At least a part of the fourth metal-wiring layer1301 is equipotential to the first metal block 421 or the third metalblock 423. In the embodiment, the power module 1 h includes the fourthmetal-wiring layer 1301 disposed under the second metal block 422, andthe fourth metal-wiring layer 1301 is connected to the third metal block423. An insulating material is disposed between the second metal block422 and the fourth metal-wiring layer 1301 for insulating the secondmetal block 422 from the fourth metal-wiring layer 1301. In theembodiment, the main heat dissipation paths of the first switch 451 andthe second switch 452 are transferred to the first heat dissipatingdevice 1002 through the first metal block 421 and the third metal block423. Therefore, there is no major impact on the heat dissipationefficiency of the power module 1 h by disposing the insulating materialand the fourth metal-wiring layer 1301 under the second metal block 422.

On the other hand, it should be noted that in the embodiment, there is aparasitic capacitance generated between the O electrode (refer to FIG.2B) and the heat sink, and there is also a parasitic capacitancegenerated between the heat sink and the control circuit. There is alow-impedance connection between the control circuit and the Nelectrode. In that, an electrical circuit loop is formed from the Oelectrode to the heat dissipation device, from the heat dissipationdevice to the control circuit, from the control circuit to the Nelectrode, and then from the N electrode to the O electrode. When thevoltage between the O electrode and the N electrode is changed, theabove loop will generate a common mode current, which will generate avoltage drop in the control circuit. The voltage drop is superimposed onthe control signal or the sampling signal to cause interference. Settingthe N electrode between the O electrode and the heat dissipation deviceis equivalent to connect a low impedance branch in parallel between theO electrode and the N electrode. Therefore, most of the common modecurrent is shunted to this branch. Thus, the voltage drop caused by thecommon-mode current on the control loop is reduced greatly, and theinterference to the control signal and the sampling signal is avoidedeffectively.

Notably, in the embodiment, the first metal block 421 and the thirdmetal block 423 are both quiet grounds. That is, the potential on thefirst metal block 421 and the potential on the third metal block 423 donot have a high-frequency voltage change. For example, the frequency ofthe potential change on the first metal block 421 and the third metalblock 423 is much lower than the switching frequency of the first switch451 and the second switch 452 in the power module 1 h. For example, thefrequency of the potential change on the first metal block 421 and thethird metal block 423 is less than 1/10 of the switching frequency. Inother words, the potentials of the first metal block 421 and the thirdmetal block 423 are relatively stable, the fourth metal-wiring layer1301 disposed under the second metal block 422 is at the same potentialas the first metal block 421. In other embodiments, a part of the fourthmetal-wiring layer 1301 has the same potential as the first metal block421, and another part of the fourth metal-wiring layer 1301 has the samepotential as the third metal block 423.

FIG. 18 is a schematic cross-sectional view illustrating a power moduleaccording to a tenth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1i are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the heights of thebottom surfaces of the first metal block 421, the second metal block 422and the third metal block 423 are different. The distance from thebottom surface of the second metal block 422 to the bottom surface 103of the carrier board 410 is greater than the distances from the bottomsurfaces of the first metal block 421 and the third metal block 423 tothe bottom surface 103 of the carrier board 410. Thereby, the gapbetween the second metal block 422 and the heat dissipation device isincreased to reduce the parasitic capacitance of the second metal block422 to the bottom surface. The common mode current relative to the heatdissipation device is further eliminated. In the embodiment, thestructure of the power module 1 i is realized by the prefabricated metalblocks with different thicknesses. Certainly, the present disclosure isnot limited thereto. The second metal block 422 does not generate toomuch heat therefrom, so that the heat dissipation capability of thepower module 1 i is not influenced.

FIG. 19 is a schematic cross-sectional view illustrating a power moduleaccording to an eleventh embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1j are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the bare chips of thefirst switch 451 and the second switch 452 of the power module 1 j areboth disposed above the second metal block 422. The first switch 451 isdisposed with the first pad T1 facing upward, the first pad T1 isconnected to the first metal block 421, and the second pad T2 isconnected to the second metal block 422. The second switch 452 isdisposed with the first pad T1′ facing downward, the first pad T1′ isconnected to the second metal block 422, and the second pad T2′ isconnected to the third metal block 423.

In the embodiment, the potential of the second metal block 422 has acertain voltage jump. For example, the frequency of the potential changeon the second metal block 422 is more than 1/10 of the frequency of thefirst switch 451 and the second switch 452. The first pad T1 on thesurface of the first switch 451 and the second pad T2′ on the surface ofthe second switch 452 are stable voltage nodes, that is, a quiet ground.An electromagnetic shielding layer between the second metal block 422and the driving circuit or the control circuit thereabove is formed bythe first pad T1 on the surface of the first switch 451 and the secondpad T2′ on the surface of the second switch 452. Thus, theelectromagnetic interference caused by the voltage jump of the secondmetal block 422 on the signal of the driving circuit or control circuitdisposed thereabove is suppressed.

FIG. 20 is a schematic cross-sectional view illustrating a power moduleaccording to a twelfth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1k are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the first switch 451and the second switch 452 of the power module 1 k are both verticaldevices. In the embodiment, the first switch 451 and the second switch452 are both disposed on the upper surface 102 of the carrier board 410with the first pad T1, T1′ facing downward.

FIG. 21 is a schematic cross-sectional view illustrating a power moduleaccording to a thirteenth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1m are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the first switch 451and the second switch 452 of the power module 1 m are both verticaldevices. In the embodiment, the first switch 451 is disposed with thefirst pad T1 facing upward, and the second switch 452 is disposed withthe first pad T1′ facing upward. In other embodiment, the first switch451 and the second switch 452 are planar devices.

FIG. 22 is a schematic cross-sectional view illustrating a power moduleaccording to a fourteenth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1n are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the first switch 451′and the second switch 452′ of the power module 1 n are both planardevices, such as GaN HEMT or planar MOSFET. The bare chips of the firstswitch 451′ and the second switch 452′ includes a first pad, a secondpad and a third pad (not shown), which are located at surfaces of thebare chips. The surfaces are defined as the functional surfaces T0, TO′of the bare chips. In the embodiment, the functional surfaces T0, T0′ ofthe bare chips of the first switch 451′ and the second switch 452′ arethe lower surfaces. The first switch 451′ and the second switch 452′ arepackaged components, and the electrodes are led out through metalconnectors on the lower surfaces. In other embodiments, the uppersurfaces of the first switch 451′ and the second switch 452′ includemetal connectors, which are completely exposed on the packaged surfaces.In the embodiment, the first switch 451′ and the second switch 452′ areboth disposed on the upper surface 102 of the carrier board 410 with thefunctional surfaces T0, T0′ of the bare chips facing downward.

FIG. 23 is a schematic cross-sectional view illustrating a power moduleaccording to a fifteenth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1o are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the first switch 451′and the second switch 452′ of the power module 10 are both planardevices. In the embodiment, the first switch 451′ and the second switch452′ are both disposed on the carrier board 410 with the functionalsurfaces T0, T0′ of the bare chips facing upward.

FIG. 24 is a schematic cross-sectional view illustrating a power moduleaccording to a sixteenth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1p are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the first switch 451′and the second switch 452′ of the power module 1 p are planar devices,such as GaN HEMT, which is in the form of flip chip or not. The chipbecomes a packaged component through secondary packaging. The packagedcomponent is flip-chip mounted on the carrier board 410. The bare chipareas of the first switch 451′ and the second switch 452′ are overlappedwith the projections of the first metal block 421 and the second metalblock 422 on the lower surface 103 of the carrier board 410, and theoverlap ratio is relatively the same. In that, the first metal block421, the second metal block 422 and the third metal block 423 areprovided for conduction and heat dissipation at the same time. It shouldbe noted that only the main power electrodes of the first switch 451′and the second switch 452′ are shown in FIG. 24.

In the embodiment, the carrier board 410 of the power module 1 p furtherincludes a first connection portion 4211. The first metal block 421 isconnected to the first metal-wiring layer 431 through the firstconnection portion 4211. The first connection portion 4211 and the firstmetal-wiring layer 431 are located at the same layer. Preferably but notexclusively, the first connection portion 4211 and the firstmetal-wiring layer 431 are located at the same height.

FIG. 25 is a schematic cross-sectional view illustrating a power moduleaccording to a seventeenth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1q are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the carrier board 410of the power module 1 q further includes a second connection portion4212. The first metal block 421 is connected to the first metal-wiringlayer 431 through the second connection portion 4212. The secondconnection portion 4212 includes a horizontal portion 4213 and a bendingportion 4214. The horizontal portion 4213 and the second metal-wiringlayer 432 are located at the same layer. Moreover, the bending portion4214 is connected between the horizontal portion 4123 and the firstmetal-wiring layer 432.

FIG. 26 is a schematic cross-sectional view illustrating a power moduleaccording to an eighteenth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1r are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the clamping component440 of the power module 1 r is located at the right side of the secondswitch 452. Certainly, in other embodiments, the clamping component 440is located at the left side of the first switch 451. Preferably but notexclusively, in the embodiment, the clamping component 440 is acapacitor. In other embodiments, the clamping component 440 is forexample but not limited to the clamping circuit shown in FIG. 3, orother electronic devices or electronic circuits with a clampingfunction.

In the embodiment, the first switch 451 and the second switch 452correspond to the switch S1 and the switch S2 connected in series asshown in FIG. 2B. The clamping component 440 corresponds to thecapacitor Cin shown in FIG. 2B. The capacitor Cin is connected inparallel with the branch of the switch S1 and the switch S2 connected inseries, so as to clamp the voltage at both pads of the switch S1 and theswitch S2. In the embodiment, the carrier board 410 is a printed circuitboard including a first metal block 421, a second metal block 422 and athird metal block 423 disposed therein. Corresponding to FIG. 2B, thefirst metal block 421 is connected to the P electrode, the second metalblock 422 is connected to the O electrode, and the third metal block 423is connected to the N electrode. The second metal block 422 is locatedbetween the first metal block 421 and the third metal block 423.Preferably but not exclusively, the first metal block 421, the secondmetal block 422 and the third metal block 423 may be prefabricated metalblocks, including preformed thick metal materials.

FIG. 27 is a schematic cross-sectional view illustrating a power moduleaccording to a nineteenth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module10 a are similar to those of the power module 1 a of FIG. 4, and are notredundantly described herein. In the embodiment, the power module 10 aincludes four pairs of half bridges of the first switch 451 and thesecond switch 452. The four pairs of half bridges are connected inparallel to form the power module 10 a. In the embodiment, a clampingcomponent 440 is provided between each pair of the first switch 451 andthe second switch 452. Preferably but not exclusively, the electrode padcorresponding to the clamping component 440 is led out by the samestructure as that shown in the power module 1 a of FIG. 4. In otherembodiments, the electrode pad corresponding to the clamping component440 is led out through the surface copper between the adjacent firstswitch 452 and second switch 452. A pair of the first switch 451 and thesecond switch 452 corresponds to one or more clamp capacitors. Thespecific number is adjustable according to the practical requirements.In the embodiment, a driving clamp circuit element 441 is furtherdisposed between the first switch 451 and the second switch 452.Moreover, a driving control area 2301 is provided on the periphery ofthe switches, and the driving control area 2301 is used for bus lineconnection and disposing the required driving and controllingcomponents. It should be noted that the surface wiring in FIG. 27 isonly for illustration. The present disclosure is not limited thereto.

FIG. 28 is a schematic cross-sectional view illustrating a power moduleaccording to a twentieth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module10 b are similar to those of the power module 10 a of FIG. 27, and arenot redundantly described herein. In the embodiment, the electrodes ofthe half-bridge power module 10 b are led out according to anotherlayout. The P electrode and the N electrode are extended and led outdirectly through the first metal block 421 and the third metal block 423(refer to FIG. 1A), respectively, so as to meet the pin requirements ofdifferent systems and adjust the creepage distance between theelectrodes.

In the embodiment, the power module 10 b further includes a moldingmaterial (not shown), and the molding material covers the first switch451 and the second switch 452, respectively. In order to reduce thehorizontal electrical gap between the exposed electrodes of theswitches, molding, potting, spray coating, underfilling and othermethods can be used for molding, so that the air insulation is replacedby the solid insulation. In this way, the electrical gap is reducedgreatly, and the size of the carrier board 410 is reduced.

In the embodiment, in order to make the insulating material easy to beapplied to the power device 10 b, when the bare chip is packaged, an airzone is formed on the plane of electrodes and located between theterminals, such as between the drain and the source of the MOSFET. Inthe embodiment, an air zone without the molding material is formedbetween the first pad T1 and the second pad T2 of the first switch 451.Moreover, an air zone without the molding material is formed between thefirst terminal T1′ and the second terminal T2′ of the second switch 452.For example, the first switch 451 and the second switch 452 have thesame structure as the power device 1201 shown in FIG. 29. The twoelectrodes on the first side of the power device 1201 are led outthrough the terminal 1202 and the terminal 1203, respectively. Thesecond side of the power device 1201 and the terminal 1203 are connectedthrough the connecting bridge 1204. The air zone 1206 without themolding material 1205 is formed between the terminal 1202 and theterminal 1203. With the arrangement of the air zone 1206, it facilitatesthe insulating material to be added subsequently between the two highvoltage terminals for filling. In other embodiments, a recess or an openarea is formed between the two terminals of the carrier board 410 tofacilitate the filling process of the insulating material. Furthermore,the bare chip of the power device can be directly mounted on the carrierboard 410. The side of the bare chip adjacent to the carrier board 410is electrically connected to the surface pad of the carrier board 410 bywelding or sintering. Another side of the bare chip away from thecarrier board 410 is electrically connected to the carrier board 410through metal bridges or bonding wires. Thereafter, the whole structureis protected by the molding to form the insulation protection. Comparedwith the discrete device, the bare chip is mounted directly, and it isadvantageous for reducing the additional connection impedance caused bypackaging of the discrete devices. Certainly, the present disclosure isnot limited thereto.

In the embodiment, each pair of the first switch 451 and the secondswitch 452 in the power module 10 b are connected in series, andconfigured to form a circuit of a half-bridge structure as shown in thepower module 1 a of FIG. 4. In an embodiment, the series connection ofthe first switch 451 and the second switch 452 is used as a part of thecircuit and applied to a full-bridge structure to form the structure ofpower module 10 c, which is the twenty-first embodiment of the presentdisclosure as shown in FIG. 30. Certainly, in other embodiments, theseries connection of the first switch 451 and the second switch 452 isapplied to various more complex circuit structures, such as TNPC, DNPC,ANPC and other neutral point clamping (NPC) circuits. As long as thecircuit has a structure in which the first switch 451 and the secondswitch 452 are connected in series, the power module 10 b in theforegoing embodiment can be applied without limitation.

FIG. 31 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-second embodiment of the present disclosure. Asshown in FIG. 31, the power module 10 d includes a surface mount (SMT)structure. The terminal 2101 is located on the upper surface of thepower module 10 d, connected to the first metal block 421, the secondmetal block 422 and the third metal block 423 (refer to FIG. 1A), andconnected to the electrodes on a driving board, so that a more flexibleterminal position design is realized.

FIG. 32 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-third embodiment of the present disclosure. Theterminal 2201 of the power module 10 e is a press-fit structure, whichis easier to install and provides better terminal connectionreliability.

In other embodiments, the power module 10 e further includes a drivingcircuit for driving the first switch 451 and the second switch 452.

FIG. 33 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-fourth embodiment of the present disclosure. Inthe embodiment, the structures, elements and functions of the powermodule 10 f are similar to those of the power module 10 a of FIG. 27,and are not redundantly described herein. In the embodiment, the powermodule 10 f includes a driving/control region 2301. Preferably but notexclusively, a driving chip, a control chip, a protection circuit, aresistor, a capacitor and other components are integrated in thedriving/control region 2301 to realize driving signal output, Millerclamping, protection of signal collection and processing, communicationwith superior control and other functions.

In addition, according to the aforementioned structural concept of thepower module 1 a, the present disclosure further provides amanufacturing method of the power module. As shown in FIGS. 34A to 34E,the manufacturing method of the power module of the present disclosureincludes the following steps. In the first step, the first metal block421, the second metal block 422 and the third metal block 423 areprefabricated, as shown in FIG. 34A. In the second step, theprefabricated first metal block 421, the second metal block 422, thethird metal block 423 and a core board 100 are pressed into an integralcarrier board by insulating materials. The second metal block 422 islocated between the first metal block 421 and the third metal block 423,as shown in FIG. 34B. In the third step, a wiring processing isperformed on the carrier board through drilling, copper sinking,electroplating and etching in the PCB process, so as to form thestructure shown in FIG. 35. The first metal-wiring layer 431 and thesecond metal-wiring layer 432 are formed on the carrier board 410 asshown in FIG. 34C. In the fourth step, a first switch 451, a secondswitch 452 and a clamping component 440 are connected to the carrierboard 410. In the embodiment, the first switch 451 and the second switch452 are connected to the clamping component 440 through the firstmetal-wiring layer 431 and the second metal-wiring layer 432. Each ofthe first switch 451 and the second switch 452 has a first pad T1, T1′and a second pad T2, T2′. The first pad T1 of the first switch 451 isconnected to the first metal block 421. the second pad T2 of the firstswitch 451 is connected to the second metal block 422 through the secondmetal-wiring layer 432. The first pad T1′ of the second switch 452 isconnected to the second metal block 422 through the second metal-wiringlayer 432. The second pad T2′ of the second switch 452 is connected tothe third metal block 423, as shown in FIG. 34D. In the fifth step, thegaps between the first switch 451 and the carrier board 410 and betweenthe second switch 452 and the carrier board 410 are filled with theinsulating material 104 by potting or injection to perform electricalinsulation and environmental protection, as shown in FIG. 34E.

Notably, the core board 100 is not necessary in the above process, andthe fifth step is not necessary.

Notably, in other embodiments, the first metal block, 421, the secondmetal block 422 and the third metal block 423 are formed into individualcomponents by molding or dispensing, and then laminated to form thecarrier board 410 in one piece by insulating materials.

Notably, the process of forming the insulating material between themetal-wiring layers is for example but not limited to a PCB laminationprocess. In an embodiment, it is achieved by means such as chemicalvapor deposition or spraying, to meet different withstand voltage andthickness requirements. In other embodiments, one or more processingmethods are used to form the composite insulating material.

FIG. 36 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-fifth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power moduleis are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, in the carrier 410 ofthe power module 1 s, a part of the first metal block 421 and a part ofthe third metal block 423 are extended below the O electrode. Therequire shapes of the first metal block 421 and the third metal block423 are prefabricated. The metal conductive layer for the O electrode isrealized by the PCB process. Since the copper blocks of the first metalblock 421 and the third metal block 423 are larger in the widthdirection, the heat dissipation capability is further increased. At thesame time, the first metal block 421 and the third metal block 423 arefurther extended below the O electrode, and it is help to realize theEMI shielding. In the embodiment, the first metal block 421 and thethird metal block 423 need to perform heat dissipation and conductionfunctions at the same time, and the second metal block 422 only performsconduction functions. Preferably but not exclusively, the first metalblock 421 and the third metal block 423 are formed by prefabricatedmetal blocks. The second metal block 422 is formed by a conventionalthick copper process of PCB, such as laminating pre-prepared copperfoil, electroplating copper or thickening plating based on thin copper.In an embodiment, the second metal block 422 is a metal conductor formedby a PCB process with the same thickness as the first metal-wiring layer431 or the second metal-wiring layer 432.

FIG. 37 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-sixth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1t are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the carrier board 410of the power module 1 t includes the bare chips of the first switch 451and the second switch 452 located above the second metal block 422. Thesecond metal block 422 is the main heat dissipation path. Preferably butnot exclusively, the second metal block 422 of the carrier board 410 isa prefabricated metal block. The P electrode and N electrode are formedby conventional thick copper processes of PCB, such as laminatingpre-prepared copper foil, electroplating copper or thickening platingbased on thin copper. Certainly, the first metal block 421 and the thirdmetal block 422 are metal conductors with the same thickness as thefirst metal-wiring layer 431 or the second metal-wiring layer 432 formedby a PCB process.

FIG. 38 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-seventh embodiment of the present disclosure. Inthe embodiment, the structures, elements and functions of the powermodule 1 u are similar to those of the power module 1 a of FIG. 5, andare not redundantly described herein. In the embodiment, the carrier 410of the power module 1 u includes the first metal-wiring layer 431 andthe second metal-wiring layer 432 below the clamping element 440, whichhave projections at least partially overlapped on the carrier board 410.The current direction of the clamping circuit in the overlapped portionof the first metal-wiring layer 431 is opposite to that in theoverlapped portion of the second metal-wiring layer 432, so that thehigh frequency loop inductance is further reduced.

Moreover, please refer to FIG. 29. The manufacturing method of the powermodule provided by the embodiments of the present disclosure furtherincludes the following step. A molding material 1205 is formed to coverthe first switch 451 and the second switch 452. Preferably but notexclusively, an air zone 1206 without the molding material is formedbetween the first pad T1 and the second pad T2 of the first switch 451.

FIG. 40 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-eighth embodiment of the present disclosure. Inthe embodiment, the structures, elements and functions of the powermodule 1 v are similar to those of the power module 1 a of FIG. 5, andare not redundantly described herein. In the embodiment, the powermodule 1 v includes a carrier board 410, a first switch 451, a secondswitch 452, at least one metal block 421, 422, 423, a clamping component440 and a metal conductive component 461. The carrier board 410 includesan upper surface 102, a lower surface 103, a positive terminal connectedto the P electrode and a negative terminal connected to the N electrode.The first switch 451 and the second switch 452 are disposed on the uppersurface 102 and connected in series to form a bridge arm electricallyconnected between the positive terminal and the negative terminal. Theat least one metal block 421, 422, 423 is disposed between the uppersurface 102 and the lower surface 103, and electrically connected to thefirst switch 451 and/or the second switch 452. The clamping component440 is disposed on the upper surface 102 and electrically connected inparallel with the bridge arm through the carrier board 410. The metalconductive component 461 is connected from a common node of the firstswitch 451 and the second switch 452 to an output terminal, such as theO electrode. The metal conductive component 461 is located at a side ofthe first switch 451 and the second switch 452 away from the uppersurface 102. In the embodiment, the first pad T1 of the first switch 451is connected to the first metal block 421. The second pad T2 of thefirst switch 451 is connected to the first pad T1′ of the second switch452 through the trace 4321 on the second metal-wiring layer 432, andconnected to the second metal block 422. Since the area of the trace4321 on the second metal-wiring layer 432 connected to the second pad T2of the first switch 451 and the first pad T1′ of the second switch 452is very small, the capacitor formed between the trace 4321 and the trace4322 having the same polarity as the N electrode on the firstmetal-wiring layer 431 is small. Since the capacitor is connectedbetween the first pad T1′ of the second switch 452 and the N electrode,it becomes a part of the output capacitor between the first pad T1′ andthe second pad T2′ of the second switch 452. The capacitor has a greaterimpact on the switching loss of the switching component. When the outputcapacitor is small, the switching loss of the switch is also small.Since the overlapping area between the trace 4321 and the N electrode issmall, the capacitor generated therefrom is also small accordingly. Inother embodiments, the trace 4321 on the second metal-wiring layer 432connected to the second pad T2 of the first switch 451 and the first padT1′ of the second switch 452 are correspondingly disposed above the Pelectrode. The second pad T2′ of the second switch 452 is connected tothe third metal block 423, and the first switch 451 and the secondswitch 452 are connected to the clamping element 440 through the firstmetal-wiring layer 431 and the second metal-wiring layer 432. Theclamping component 440 is located at the left side of the first switch451 or at the right side of the second switch 452. In other embodiments,the clamping components 440 are disposed on the left side of the firstswitch 451 and the right side of the second switch 452 at the same time.In the embodiment, the first switch 451 and the second switch 452 arediscrete devices. The metal block in the present disclosure isconsidered as a metal conductor with a thickness greater than 0.3 mm.

FIG. 41 is a schematic cross-sectional view illustrating a power moduleaccording to a twenty-ninth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1w are similar to those of the power module 1 a of FIG. 5, and are notredundantly described herein. In the embodiment, the power module 1 wincludes the first switch 451 and the second switch 452, which areintegrally formed as a switch assembly 450. The second pad T2 of thefirst switch 451 and the first pad T1′ of the second switch 452 areconnected through the metal conductive component 461 in the switchassembly 450. There is no need to dispose the trace 4321 on the carrierboard 410 for connecting the second pad T2 of the first switch 431 andthe first pad T1′ of the second switch 432. Compared with the trace 4321in FIG. 40, the distance between the metal conductive component 461 andthe trace 4322 is longer, and the capacitor between the metal conductivecomponent 461 and the trace 4322 is smaller. Thus, the output capacitorsof the first switch 451 and the second switch 452 are also smaller, andthe switching losses of the first switch 451 and the second switch 452are correspondingly reduced.

FIG. 42 is a schematic cross-sectional view illustrating a power moduleaccording to a thirtieth embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1x are similar to those of the power module 1 v of FIG. 40, and are notredundantly described herein. In the embodiment, the first pad T1 of thefirst switch 451 is connected to the first metal block 421. The secondpad T2 of the first switch 451 is connected to the first pad T1′ of thesecond switch 452 through the metal conductive component 461. The secondpad T2′ of the second switch 452 is connected to the third metal block423. The first pad T1 of the first switch 451 and the second pad T2′ ofthe second switch 452 are connected to the clamping component 440. Theclamping component 440 is located between the first switch 451 and thesecond switch 452, and the metal conductive component 461 is locatedabove the clamping component 440 and is connected to the first switch451 and the second switch 452. The first switch 451 and the secondswitch 452 are discrete devices. In the embodiment, the metal conductivecomponent 461 includes a slot 4610, and the clamping component 440 isaccommodated in the slot 4610. Different from the power module 1 v inFIG. 40, the power module 1 x does not connect the first switch 451 andthe second switch 452 through the trace on the metal-wiring layer of thecarrier board 410. In the embodiment, the corresponding pad s of thefirst switch 451 and the second switch 452 are connected through themetal conductive component 461 out of the carrier board 410. Referringto FIG. 2B, in the embodiment, the corresponding polarity of the metalconductive component 461 is the O electrode, and the distance betweenthe metal conductive component 461 and the P electrode or the Nelectrode under the clamping component 440 is relatively longer. In thisway, the capacitor formed between the O electrode and the P electrode orthe N electrode is small. The capacitor formed between the O electrodeand the P electrode is a part of the output capacitance between thefirst pad T1 and the second pad T2 of the first switch 451. Thecapacitor formed between the O electrode and the N electrode is a partof the output capacitance between the firs pad T1′ and the second padT2′ of the second switch 452. When the capacitor formed between the Oelectrode and the P electrode and the capacitor formed between the Oelectrode and the N pole is small, the switching losses of the firstswitch 451 and the second switch 452 are correspondingly small.

FIG. 43 is a schematic cross-sectional view illustrating a power moduleaccording to a thirty-first embodiment of the present disclosure. In theembodiment, the structures, elements and functions of the power module 1y are similar to those of the power module 1 x of FIG. 42, and are notredundantly described herein. In the embodiment, the first switch 451and the second switch 452 are an integral switch assembly, and thesecond pad T2 of the first switch 451 and the first pad T1′ of thesecond switch 452 are connected with each other through the metalconductive component 461 inside the switch assembly. The main part ofthe metal conductive component 461 has a longer longitudinal distancefrom the first metal block 421 connected to the P electrode and from thethird metal block 423 connected to the N electrode. Therefore, thecapacitor formed between the O electrode and the P electrode is small,the capacitor formed between the O electrode and the N electrode issmall, and the switching losses of the first switch 451 and the secondswitch 452 are correspondingly small.

FIG. 44 is a schematic cross-sectional view illustrating a power moduleaccording to a thirty-second embodiment of the present disclosure. Inthe embodiment, the structures, elements and functions of the powermodule 1 z are similar to those of the power module 1 v of FIG. 40, andare not redundantly described herein. In the embodiment, the firstswitch 451′ and the second switch 452′ are both planar devices with thefunctional surfaces T0, T0′ facing the upper surface 102 of the carrierboard 410. The first pad of the first switch 451′ is connected to thefirst metal conductor 421, and the second pad of the first switch 451′is connected to an eighth metal block 428. The first pad of the secondswitch 452′ is connected to a ninth metal block 429. The second pad ofthe second switch 452′ is connected to the third metal block 423. Theeighth metal block 428 and the ninth metal conductor 429 are connectedthrough the metal conductive component 461. The first pad of the firstswitch 451′ and the second pad of the second switch 452′ are connectedto the clamping component 440. The clamping component 440 is locatedbetween the first switch 451′ and the second switch 452′. Thelongitudinal distance between the metal conductive component 461 locatedabove the clamping component 440 and the first metal block 421 below theclamping component 440 is relatively long. Moreover, the longitudinaldistance between the metal conductive component 461 located above theclamping component 440 and the third metal block 423 below the clampingcomponent 440 is relatively long. The metal conductive component 461 isconnected to the O electrode, the first metal block 421 is connected tothe P electrode, and the third metal block 421 is connected to the Nelectrode. Therefore, the capacitance formed between the O electrode andthe P electrode is small, and the capacitance formed between the Oelectrode and the N electrode is small. The switching losses of thefirst switch 451′ and the second switch 452′ are correspondingly small.

From the above descriptions, the present disclosure provides a carrierboard and a power module using the same. By optimizing the arrangementof each component, the purpose of reducing the parasitic inductance andthe EMI is achieved. It facilitates the power module structure to beassembled easily and firmly. At the same time, it is beneficial toreduce the volume of the power module and improve the entire powerdensity of the power module. By utilizing a carrier board including twometal-wiring layers and at least one metal block to connect two switchesin series to form a bridge arm, the area of the high-frequency loop isreduced, and the corresponding loop parasitic inductance is reduced. Inaddition, when the bridge arm formed by the two switches and a clampingcomponent of the power module are electrically connected in parallel onthe carrier board through the two metal-wiring layers, it is helpful forreducing the clamping inductance in the power module. With the at leastone metal block embedded in the carrier board, it is more helpful forimproving the heat dissipation performance of the power module. Bypartially overlapping the projections of the at least two metal-wiringlayers, the at least one metal block and the two switches connected toeach other in series on the surface of the carrier board, two highfrequency loops decoupled from each other are formed, and the parasiticinductance in the two high-frequency loops is reduced. The current ofone first high-frequency loop flows through the metal-wiring layer onthe surface of the carrier board, and the current of anotherhigh-frequency loop crosses through the metal-wiring layer on thesurface of the carrier board. Notably, the current that flows throughthe metal-wiring layer in the horizontal direction can be ignored. Atleast, the two high-frequency loops are partially decoupled, and themutual influence is eliminated. Moreover, it is easy to realize theconnection of the carrier board with the bridge arm including the twoseries-connection switches. It is beneficial for reducing the cost andenhancing the reliability. Since the bridge arm including twoseries-connection switches is disposed on the carrier board including atleast one metal block embedded therein, it facilities the power moduleto combine with two heat dissipation devices to achieve the double-sidedheat dissipation and reduce the thermal resistance. Furthermore, thepurposes of reducing the costs, enhancing the reliability of the powermodule and improving the heat-dissipation capacity are achieved. Themetal-wiring layer on the surface of the carrier board can be realizedwith a thinner thickness, and combined with the metal blockprefabricated and embedded within the carrier board to reduce themanufacturing costs and further enhance the reliability of the carrierboard. When the two switches and the clamping component of the powermodule are directly disposed on the carrier board, it is beneficial forsimplifying the assembly structure, reducing the cost, simplifying themanufacturing process, and improving the yield and reliability of theproduct. By arranging the metal conductive component on the side of theswitches and the clamping component away from the carrier board, themetal conductive component is kept away from the trace of carrier board,which connects the switches and the clamping component to the positiveterminal and the negative terminal therethrough, so that the outputcapacitance formed by the switches of the power module is reduced, andthe parasitic inductances in the two high frequency loops areeliminated. An optimized power module is achieved. Moreover, the metalconductive component and the bridge arm including two switches connectedin series can be prefabricated into an integrated structure, and theconnection with the carrier board is easy to realize. It is beneficialfor reducing the cost and enhancing the reliability. Two switches areconnected to each other in series to form a bridge arm and disposed onthe carrier board, and the bridge arm is formed by connecting twoswitches in series through the metal conductive component. Moreover, thebridge arm is connected with the clamping component in parallel throughthe carrier board, so as to form two high frequency loops decoupled fromeach other. Since the two high frequency loops are partially decoupled,the mutual influence is eliminated. Moreover, the metal-wiring layer onthe surface of the carrier board can be realized with a thinnerthickness, and combined with an integrated structure prefabricated bythe metal conductive component and the two switches, so as to reduce themanufacturing costs. When the two switches and the metal conductivecomponent of the power module are directly disposed on the carrierboard, it is beneficial for simplifying the assembly structure, reducingthe cost, simplifying the manufacturing process, and improving the yieldand reliability of the product.

While the disclosure has been described in terms of what is presentlyconsidered to be the most practical and preferred embodiments, it is tobe understood that the disclosure needs not be limited to the disclosedembodiment. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures.

What is claimed is:
 1. A carrier board, comprising: a main bodycomprising at least two terminals and at least one surface, wherein theat least two terminals are disposed on the at least one surface; atleast two metal-wiring layers forming at least two parts of metal tracesand connecting to the at least two terminals, respectively, wherein atleast one of the two metal-wiring layers is disposed in the main body;and at least one metal block embedded in the main body and connected toone of the at least two terminals, wherein a thickness of the at leasttwo parts of metal traces is less than a thickness of the at least onemetal block, wherein the at least two terminals connected by the atleast two parts of the metal traces have a loop inductance, which isless than or equal to 1.4 nH when the loop inductance is calculated at afrequency greater than 1 MHz.
 2. The carrier board according to claim 1,wherein the at least two metal-wiring layers comprises a firstmetal-wiring layer and a second metal-wiring layer, and the at least onesurface comprises an upper surface and a lower surface, wherein thefirst metal-wiring layer and the second metal-wiring layer are locatedat a side of the at least one metal block facing the upper surface. 3.The carrier board according to claim 2, further comprising a thirdmetal-wiring layer, wherein the third metal-wiring layer is located at aside of the at least one metal block facing the lower surface, and atleast one part of the third metal-wiring layer is equipotential with theat least one metal block.
 4. The carrier board according to claim 2,further comprising a first thermal-conductive and insulating material,wherein the first thermal-conductive and insulating material is disposedon the lower surface.
 5. The carrier board according to claim 1, whereinthe at least one metal block is a prefabricated metal conductor and hasa thickness greater than 0.3 mm.
 6. The carrier board according to claim1, wherein a projection of the at least one metal block on the at leastone surface is at least partially overlapped with a projection of the atleast two terminals on the at least one surface.
 7. The carrier boardaccording to claim 1, wherein the at least two terminals comprise atleast three terminals disposed on the at least one surface, wherein theat least three terminals are configured to form a positive terminal, anegative terminal and an output terminal of a power module.
 8. Thecarrier board according to claim 7, wherein the at least one metal blockcomprises a first metal block, a second metal block and a third metalblock, wherein the second metal block is disposed between the firstmetal block and the third metal block, and the second metal block isconnected to the output terminal.
 9. The carrier board according toclaim 7, wherein the power module comprises two switches connected toeach other in series between the positive terminal and the negativeterminal, and the output terminal is electrically connected to a commonnode of the two switches, wherein the at least two metal-wiring layersare located between the two switches and the at least one metal block.10. A power module comprising: a carrier board comprising: a main bodycomprising at least two terminals, an upper surface and a lower surface,wherein the at least two terminals are disposed on the upper surface; atleast two metal-wiring layers forming at least two parts of metal tracesand connecting to the at least two terminals, respectively, wherein atleast one of the two metal-wiring layers is disposed in the main body;and at least one metal block embedded in the main body and connected toone of the at least two terminals, wherein a thickness of the at leasttwo parts of metal traces is less than a thickness of the at least onemetal block; and two switches disposed on the upper surface andconnected to each other in series through the at least two terminals toform a bridge arm, wherein a projection of the at least one metal blockon the lower surface is at least partially overlapped with a projectionof the two switches on the upper surface.
 11. The power module accordingto claim 10, wherein the at least two terminals comprises at least threeterminals, and the at least three terminals comprises a positiveterminal, a negative terminal and an output terminal, wherein the bridgearm is electrically connected between the positive terminal and thenegative terminal, and a common node of the two switches is electricallyconnected to the output terminal, wherein the at least two metal-wiringlayers are located between the two switches and the at least one metalblock.
 12. The power module according to claim 10, further comprising aclamping component disposed on the upper surface and electricallyconnected in parallel with the bridge arm through the at least twometal-wiring layers, wherein the at least two metal-wiring layers arelocated between the clamping component and the at least one metal block.13. The power module according to claim 12, wherein the clampingcomponent is a capacitor.
 14. The power module according to claim 10,wherein the at least two metal-wiring layers comprises a firstmetal-wiring layer and a second metal-wiring layer, and the firstmetal-wiring layer and the second metal-wiring layer are located at aside of the at least one metal block facing the upper surface.
 15. Thepower module according to claim 14, wherein the carrier board furthercomprises a third metal-wiring layer, the third metal-wiring layer islocated at a side of the at least one metal block facing the lowersurface, and at least one part of the third metal-wiring layer isequipotential with the at least one metal block.
 16. The power moduleaccording to claim 14, further comprising a clamping component, whereinthe two switches comprise a first switch and a second switch, whereinthe clamping component, the first switch and the second switch aredisposed on the upper surface, wherein the clamping component iselectrically connected in parallel with the bridge arm through the firstmetal-wiring layer and the second metal-wiring layer.
 17. The powermodule according to claim 16, wherein the at least one metal blockcomprises a first metal block, a second metal block and a third metalblock, and the first metal block, the second metal block and the thirdmetal block spatially correspond to first switch, the clamping componentand the second switch, respectively.
 18. The power module according toclaim 17, wherein the clamping component is located between the firstswitch and the second switch, and the second metal block is locatedbetween the first metal block and the third metal block.
 19. The powermodule according to claim 17, wherein each of the first switch and thesecond switch comprises a first pad and a second pad, wherein the firstpad of the first switch is connected to the first metal block, thesecond pad of the first switch is connected to the second metal blockthrough the second metal-wiring layer, the first pad of the secondswitch is connected to the second metal block through the secondmetal-wiring layer, and the second pad of the second switch is connectedto the third metal block.
 20. The power module according to claim 17,wherein the first switch and the second switch are both verticaldevices, the first switch is disposed on the carrier board with thefirst pad facing to the carrier board, and the second switch is disposedon the carrier board with the first pad facing away from the carrierboard.
 21. The power module according to claim 17, wherein a projectionof the first switch on the lower surface of the carrier board is atleast partially overlapped with a projection of the first metal block orthe second metal block on the lower surface of the carrier board, and aprojection of the second switch on the lower surface of the carrierboard is at least partially overlapped with a projection of the secondmetal block or the third metal block on the lower surface of the carrierboard.
 22. The power module according to claim 17, wherein a thicknessof the second metal block is less than a thickness of the first metalblock or the third metal block.
 23. The power module according to claim17, wherein bottom heights of the first metal block, the second metalblock and the third metal block are different.
 24. The power moduleaccording to claim 17, further comprising: a fourth metal block disposedon the lower surface of the carrier board, located under the first metalblock, and connected to the first metal block; a fifth metal blockdisposed on the lower surface of the carrier board, located under thesecond metal block, and connected to the second metal block; and a sixthmetal block disposed on the lower surface of the carrier board, locatedunder the third metal block, and connected to the third metal block. 25.The power module according to claim 10, wherein the at least one metalblock is a prefabricated metal conductor and has a thickness greaterthan 0.3 mm.
 26. The power module according to claim 10, wherein the twoswitches are both planar devices or bare chips.
 27. The power moduleaccording to claim 10, wherein the main body of the carrier boardfurther comprising a first thermal-conductive and insulating materialdisposed on the lower surface of the carrier board.
 28. The power moduleaccording to claim 10, wherein the carrier board further comprises afirst connection portion, and the at least one metal block is connectedto one of the at least two metal-wiring layers through the firstconnection portion, wherein the first connection portion and one of theat least two metal-wiring layers are located at the same layer.
 29. Thepower module according to claim 10, wherein the carrier board furthercomprises a second connection portion, and the at least one metal blockis connected to one of the at least two metal-wiring layers through thesecond connection portion, wherein the second connection portioncomprises a parallel portion and a bending portion, and the bendingportion is connected between the parallel portion and one of the atleast two metal-wiring layers.